我希望每个 ChartData 有一个自定义
maximumValue
,以便每个图表都有自己的值。
ChartData 看起来像这样(添加
totalCount
设置器)
class ChartData {
ChartData(this.x, this.y, [this.totalCount]);
final String x;
final double y;
final double? totalCount;
}
然后是它的数据实例化器
final chartData = [
ChartData('ONE', 3, 20),
ChartData('TWO', 10, 100),
];
然后在实现中,当我想从
totalCount
添加 ChartData
时,如下所示:
SizedBox(
height: 300.0,
child: SfCircularChart(series: <CircularSeries>[
// Renders radial bar chart
RadialBarSeries<ChartData, String>(
dataSource: chartData,
xValueMapper: (ChartData data, _) => data.x,
yValueMapper: (ChartData data, _) => data.y,
maximumValue: (ChartData data, _) => data.totalCount,)
])),
我收到消息:
The argument type 'double? Function(ChartData, dynamic)' can't be assigned to the parameter type 'double?'
那么我如何获得双精度值
totalCount
来用maximumValue
值而不是double
填充
Function(ChartData, dynamic)
我环顾四周但找不到答案。这可能吗?
我只需映射
chartData
就可以像这样访问 totalCount
:
SizedBox(
height: 300.0,
child: SfCircularChart(series: <CircularSeries>[
...chartData.map((data) {
// Renders radial bar chart
return RadialBarSeries<ChartData, String>(
dataSource: chartData,
xValueMapper: (ChartData data, _) => data.x,
yValueMapper: (ChartData data, _) => data.y,
maximumValue: data.totalCount,
);
}).toList(),
])),
所以这很有帮助